Electric-wire attachment



Oct. 11,1927.

A. E. CHAPMAN x-:T AL

ELECTRIC WIRE ATTACHMENT Filed Janv. 17, 1927 Patented ct. 11', 1927.

UNIT-ED STATES ALBERT EDWAED CHAPMAN, or

1,645,4ia PATENT ortica.,v

WALLINGTON, .AND CHARLES REGINALD 3130K, F BGREHAM, ENGLAN).

vELEcuatro-WIRE ATTACHMENT.

Application' filedfranaary 1.7, 192?, serial No. 161,650, ,and in Great Err-ain January 1a., rees.

f'lhis invention relates to van improved electric wire attachment, 'for use in or with electrical terminals, plugs, sockets, binding, posts and 'other parts ot electrical apparatus wherein electrical connections have to be effected.y l

VThe electric wire attachment according to the present invention' comprises a` wire receiv'ing' memberr provided on its side with io alongitudinal groove or grooves, slot or slots or vthe like, and in addition thereto'with a transverse recessor recesses extending from one side to the other in combination with a hollow clamping member adapted to engage withy the outer surtaceoif'the said wire receiving member Aand to clampthe wire with its Vend surface at or near the point the wire enters and/or leaves the longitudinal side groove for grooves or the like, or Vthe transverse hrecess or recesses, the latter-lying outside the said hollow clamping member when the wire is clamped in position.

A further feature of the invention consists in providing the wire receiving member with two diamet-rically opposite slots or grooves and in making the bridge piece left between the slots of increasing width or depth from its free end towards its other end in the plane containing the slots.

The invention also consists in embodying the 'features above referred to in interchangeable and other contact terminals, for instance such as described in specification No. 220,731.

The invention further consists in the construction of electric wire attachments hereinatter more particularly described.

The invention is illustrated by way of example in the accompanying drawings in which:

Figures l and 2 represent in elevation and plan view respectively one form of construction, whilst Figure 8 is a sectional elevation lof another orm of construction.

Referring to Figures l and 2, a cylindrical (or tapered) metal shank ci adapted to be inserted into a correspondingly shaped metal socket 'for effecting an electric contact and preferably made hollow and with helical cuts a, is provided with al screwthreaded end o which is grooved longitudinally at two diametrically opposite sides as shown at c and d in such a manner as to leave a short bridge piece e the cross section ot which in the plane of the grooves is in creased trom a narrow ridge at the'fr'ee end to the diameter of the sha-nk into whichit merges. 'lhe narrow width is preferably maintained over a certain length before it starts to increase along concave surfaces. It is, however to be understood that the increase in the width oit the bridge maybe eiiected in any other manner for instance gradually along a straight or curved line. 65,Y A transverse hole f is bored or slotted throughat the base otl the bridge, said hole or slot lying in the plane'oit' the grooves c and l and serving for the insertion ot' the end ot the wire prior to or after having been passed through one groove c and vover the ridge oi the bridge c into the other groove d. The wire is clamped in position' atA ornear the points c1, (Z1 where the wire enters or leavesthe transverse hole f or the grooves c and cl by the end surface of an ine ternally screw-threaded insulating or metal bush g.

The clamping may also be effected by the end surface oit an extended metal member adapted to constitute a socket for the reception ot' a tapered or cylindrical shank of a similar' contact terminal.

According to a further modification two concave grooves are cut into the surface of the wire receiving member along two diainetrically opposite lines, an additional transverse hole being bored at approximately the middle of the said grooves to receive the end of the wire after it has been inserted through the other transverse hole This arrangement is illustrated in Figure 3 in which li is the additional transverse hole.

Instead of forming the wire reoeivin member with an externally screW-threade surface, it may be made with a smooth surface of equal diameter from end to end or tapering towards the free end, the clamping member in that case being provided with an internal smooth4 annular surface of cylindrical or conical shape. l

The various forms of wire receiving member hereinbefore described may be so constructed that the edges adjacent to the groove or grooves are slightly resilient so that when he wire is clamped in position as above referred to it is also clamped along a smaller or greater portion within the groove or grooves.

We wish it to be understood that the details for carrying the invention into effect 110 may be modified in various respects without in any way departing from the spirit of the invention. Thus for instance the transverse hole ,t formed below the bridge piece may be formed at the base of and in the bridge piece itself7 and in such a manner as to open into the longitudinal groove or grooves; or it may be replaced by a transverse notch or notches or by a transverse annular groove. Further, the bridge piece need not extend to the upper end of the screw-threaded portion Z2. y

l/hat we claim is l. An electric wire attachment comprising a wire receiving member provided with two diametrically opposite longitudinal side grooves of sufficient depth to receive the wire except at one end of the member and with a transverse opening extending from one side to the other, in combination with a hollow clamping member which engages with the outer surface of the said wire receiving member to clamp the wire with its end surface at the point where the wire protrudes from the receiving member, the said point lying outside the said hollow clamping member when the wire is clamped in position and the transverse opening located outside said point.

2. An electric wire attachment as claimed in claim 2 and having a bridge piece between the two diametrically opposite longitudinal side grooves, the width of which bridge piece increases from its free end towards its other end in the plane containing the longitudinal grooves.

3. An electric wire attachment comprising a wire receiving member in the form of a socket having longitudinal side grooves of sufficient depth to receive the wire excepty at one end of the member and a transverse opening extending from one side to the other, in combination with a hollow clamping member which engages with the outer surface of the said wire receiving member to clamp the wire with its end surface at the point where the wire protrudes from the receiving member, the said point lying outside the said hollow clamping member when the wire is clamped in position and the transverse opening located outside said point.

4. An lelectric wire attachment .as claimed in claim l, and in which the edges of the wire receiving member adjacent to the grooves are slightly resilient for the purpose set forth.

In testimony whereof we have signed our names to this specication.

ALBERT EDWARD CHAPMAN. CHARLES REGINALD COOK. 

